package character;

/**
 * create by yctc
 **/

/**
 * 编写一个函数，其作用是将输入的字符串反转过来。输入字符串以字符数组 s 的形式给出。
 *
 * 不要给另外的数组分配额外的空间，你必须原地修改输入数组、使用 O(1) 的额外空间解决这一问题。
 *
 *
 * 示例 1：
 *
 * 输入：s = ["h","e","l","l","o"]
 * 输出：["o","l","l","e","h"]
 *
 * 示例 2：
 *
 * 输入：s = ["H","a","n","n","a","h"]
 * 输出：["h","a","n","n","a","H"]
 *  
 *
 * 提示：
 *
 * 1 <= s.length <= 105
 * s[i] 都是 ASCII 码表中的可打印字符
 */
public class ReverseString {
    public static void main(String[] args) {
        char[] s = {'H', 'a', 'n', 'n', 'a', 'h'};
        char[] s1 = {'H', 'e', 'l', 'l', 'o'};
        reverseString(s);
        reverseString(s1);
    }

    /**
     * 使用双指针，前后两两交换
     */
    public static void reverseString(char[] s) {
        int right = s.length - 1;
        char temp;
        for (int left = 0; left < right; left++) {
            temp = s[left];
            s[left] = s[right];
            s[right] = temp;
            right--;
        }
    }
}
